diagnostic tools

I have an older Titan Volta that I'd like to continue using. After installing on a new PC am noticing high idle temps (45C). This is with the fan running almost 50%! A google search suggest 30-45C as a an ok idle temp range. Does 45C seem high for GPU idle temp? Is there any good diagnostic...

I was wondering if there is a tool for computer diagnostics that is similar to the code reader car mechanics use to tell what is wrong with cars. It just seems odd that with so many advances in technology, we're still limited to swapping parts in and out of our PCs to see where the hardware...